Exoskeletons are a promising technology that could bridge the gap between unassisted human operations and conventional robots. Many studies on shoulder exoskeletons have shown great benefit in reducing strain and loads on tested muscles. The link between user preference and muscle activity reduction using exoskeletons has not been investigated. The objective of this study was to determine if user preference correlates to shoulder exoskeleton benefit. To fulfill this objective, 16 participants participated in performing 6 different simulated manufacturing aircraft tasks, using three different passive exoskeletons (Skelex, Paexo, and Evo) and No-Exoskeleton. Multiple analyses of variance (ANOVA) and multinomial logistics were run. Significant differences in muscle activity levels were found between the exoskeleton condition and the without exoskeleton condition. In every task, the use of an exoskeleton significantly reduced muscle activity. Overhead tasks, showed a greater reduction in the anterior deltoid muscle ranging from a minimum of 10% to a maximum of 17.5% when compared to tasks working at shoulder level the reduction ranged from a minimum of 5% to a maximum of 8%. Preference and performance did not correlate to the exoskeleton with the greatest muscle benefit. This may have been due to participants preferring an exoskeleton based on other factors such as comfort. Therefore, a user preference may not be an effective method in determining exoskeleton benefit.